org.apache.wicket.ajax.markup.html.navigation.paging.AjaxPagingNavigationIncrementLink.java Source code

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.wicket.ajax.markup.html.navigation.paging;

import org.apache.wicket.ajax.AjaxRequestTarget;
import org.apache.wicket.ajax.attributes.AjaxRequestAttributes;
import org.apache.wicket.ajax.markup.html.IAjaxLink;
import org.apache.wicket.markup.ComponentTag;
import org.apache.wicket.markup.html.navigation.paging.IPageable;
import org.apache.wicket.markup.html.navigation.paging.PagingNavigationIncrementLink;

/**
 * An incremental Ajaxian link to a page of a PageableListView. Assuming your list view navigation
 * looks like
 * 
 * <pre>
 * 
 *                  [first / &lt;&lt; / &lt;] 1 | 2 | 3 [&gt; / &gt;&gt; /last]
 * 
 * </pre>
 * 
 * <p>
 * and "&lt;" meaning the previous and "&lt;&lt;" goto the "current page - 5", than it is this kind
 * of incremental page links which can easily be created.
 * 
 * This link will update the pageable and itself or the navigator the link is part of using Ajax
 * techniques, or perform a full refresh when ajax is not available.
 * 
 * @since 1.2
 * 
 * @author Martijn Dashorst
 */
public class AjaxPagingNavigationIncrementLink extends PagingNavigationIncrementLink<Void> implements IAjaxLink {
    private static final long serialVersionUID = 1L;

    /**
     * Constructor.
     * 
     * @param id
     *            See Component
     * @param pageable
     *            The pageable component the page links are referring to
     * @param increment
     *            increment by
     */
    public AjaxPagingNavigationIncrementLink(final String id, final IPageable pageable, final int increment) {
        super(id, pageable, increment);

        setOutputMarkupId(true);
    }

    @Override
    protected void onInitialize() {
        super.onInitialize();
        add(newAjaxPagingNavigationBehavior(pageable, "click"));
    }

    /**
     * @param pageable
     *            The pageable component the page links are referring to
     * @param event
     *            the name of the default event on which this link will listen to
     * @return the ajax behavior which will be executed when the user clicks the link
     */
    protected AjaxPagingNavigationBehavior newAjaxPagingNavigationBehavior(IPageable pageable, String event) {
        return new AjaxPagingNavigationBehavior(this, pageable, event) {
            @Override
            protected void updateAjaxAttributes(AjaxRequestAttributes attributes) {
                super.updateAjaxAttributes(attributes);
                attributes.setPreventDefault(true);
                AjaxPagingNavigationIncrementLink.this.updateAjaxAttributes(attributes);
            }
        };
    }

    protected void updateAjaxAttributes(AjaxRequestAttributes attributes) {
    }

    /**
     * Fallback event listener, will redisplay the current page.
     * 
     * @see org.apache.wicket.markup.html.link.Link#onClick()
     */
    @Override
    public void onClick() {
        onClick(null);
    }

    /**
     * Performs the actual action of this component, performing a non-ajax fallback when there was
     * no AjaxRequestTarget available.
     * 
     * @param target
     *            the request target, when <code>null</code>, a full page refresh will be generated
     */
    @Override
    public void onClick(AjaxRequestTarget target) {
        // Tell the PageableListView which page to print next
        pageable.setCurrentPage(getPageNumber());
    }

    @Override
    protected void onComponentTag(ComponentTag tag) {
        super.onComponentTag(tag);

        // 'onclick' attribute would be set only if this component is attached
        // to HTML element different than 'a'. This 'onclick' will break Ajax's
        // event binding so here we remove it.
        // AjaxFallback is supported only with 'a' HTML element. See WICKET-4862
        tag.remove("onclick");
    }
}